Hydroxythiazole‐Based Fluorescent Probes for Fluoride Ion Detection

Abstract

This work describes the synthesis of five O‐silyloxy‐1,3‐thiazoles and their use as fast‐response “turn‐on” probes for fluoride ion detection in polar aprotic solvents and in aqueous cetyltrimethylammonium bromide micellar medium. The fluoride‐triggered deprotection of these silyl ethers results in ca. 180‐nm shifts in the fluorescence emission wavelengths. All compounds are suitable for the detection of fluoride ions with a detection limit in DMSO of 10–7 mol L–1; derivatives containing a 2‐pyridyl moiety in the thiazole system are more efficient than those with a 3‐ or 4‐pyridyl moiety. Typical anionic interferents, such as acetate or chloride, are not detected by O‐silyloxy‐1,3‐thiazoles, making these compounds very specific for fluoride.

Negative Solvatochromism of an Anionic Thiazole‐Based Dye

“…The ease of functionalization and good stability of this core structure have already led to several potential applications. 4‐Hydroxy‐1,3‐thiazole derivatives have been used as light‐harvesting ligands featuring an electron‐donating arylamine group,12 as sensitizers in dye‐sensitized solar cells (DSSCs),13 as fluorescence resonance energy transfer (FRET) energy donor in various copolymers,14 as emitting species in highly fluorescent nanoparticles,15 and as sensor molecules for the selective detection of fluoride ions 16. Very recently, fluorophores with a thiazol‐4‐olate as the electron donor were presented as highly solvatochromic Reichardt‐type betaine dyes 17.…”

Practical Chemical Kinetics in Solution

“…This technique is based on the measurement of luminescence from a sample during irradiation because most substances are promoted to an electronically excited state after the absorption of a photon. Fluorescence has been a useful method for the study of many systems [138][139][140][141], including those involving supramolecular aggregation [142]. The deactivation of this energetic state by fluorescence is fast (around 10 ns) and usually results in photons with lower energy content, that is, the emitted light has longer wavelength than the absorbed radiation.…”

Solution-and solid-state emitters with large Stokes shifts combining pyrene and 4-hydroxythiazole fluorophores

“…More important second components were found for 3a,g (9)(10)(11)(12)(13)(14)(15)(16)%. In all cases the lifetime of the sole (main) component was relatively short (~0.6-1 ns).…”